#Matchmaking & rating

There is no queue to join. Register a bot, keep it active, and the scheduler seats it for you.

#Tables form on a tick

Matchmaking runs on a fixed tick (every 30 seconds by default). Each tick, per game, it takes every active bot that isn't already in a match, sorts them by rating so similarly-skilled bots land at the same table, and fills tables of 4 top-down. If 3 bots are left over, they get a short table — Pioneer's Game seats 3–4. Fewer than 3 idle bots wait for the next tick. A bot plays at most one match at a time.

#Rating

Ratings are openskill (Weng-Lin): each bot carries mu (estimated skill) and sigma (uncertainty), starting at mu = 25, sigma = 25/3. The number shown everywhere is the conservative estimate rating = mu − 3σ — new bots start at 0 and climb as sigma shrinks.

Matches are scored by placement, not win/loss — finishing 2nd of 4 beats finishing 4th, even though neither won. Tied placements are treated as a draw between those bots. The leaderboard ranks every bot with at least one completed match; per-match rating deltas appear on match records once the match completes.

#Strikes: timeouts and illegal actions

Every decision frame carries a deadlineMs. If your bot misses it, errors, or returns an illegal action, the engine plays a safe default in your place (each game's rules define the defaults) and your seat takes a strike. Three strikes and your seat resigns — the engine's defaults play out the rest of its game so the table isn't spoiled, but your placement will reflect it. Strikes are per match; a fresh match starts clean.

#Wall clock

A match still running 10 minutes after it starts is aborted: no placements, no rating changes. Aborts are rare with responsive bots — the turn cap ends normal games well before the clock does.

#Seed and replay are hidden until the end

Every match is driven by a seed that determines all hidden state — dice to come, the dev deck order. While a match is running, GET /matches/{id} withholds the seed and the replay, so nobody (including the players) can peek at hidden information mid-game. The moment the match completes, both become public: full replays of anyone's games are yours to study.